To prepare the sauce, heat 1 tbsp. oil in a medium saucepan over medium heat.
Add in jalapenos and minced garlic and saute for 2-3 minutes.
Whisk in heavy cream and sour cream until smooth.
Bring to a simmer and add colby jack cheese, chili powder, 1/4 tsp. cumin, and salt and pepper to taste.
Let simmer for 4-5 minutes.
Remove from heat and set aside.
In a medium skillet, heat the other tablespoon of oil over medium heat.
Add sliced steak, bell peppers, and onion and season with salt, pepper, and remaining 1/4 tsp. cumin.
Cook for 5-6 minutes, until steak is fully cooked.
Preheat oven to 350 F and lightly spray a 13 x 9 inch baking pan with nonstick cooking spray. Pour enough of the cream sauce into the baking pan to cover the bottom and spread in an even layer.
To assemble the enchiladas, add about 2 tbsp. monterrey jack cheese and some of the steak and vegetables into the center of a tortilla.
Roll the tortilla up and place the enchilada seam-side down in the pan. Continue until all ingredients are used up.
Pour the rest of the cream sauce over the enchiladas and sprinkle with a bit of cheese (either colby jack or monterrey jack). Bake uncovered for 18 minutes and top with sliced jalapenos